Engine/Transmission (1998.5 - 2002) Stupid Block Heater Question

[Tulsa618]

How can you tell whether or not your block heater still works – besides the obvious … I did a search and found a lot of talk about block heaters, but found nothing that told me how to check the thing.



The service manual does not say – it just has a limited operation description, and a remove and replace procedure. But no diagnostic. When it gets cold enough, plugging it in and listening for that tell-tale hiss/crackle would certainly let me know, but I’d rather know now before it gets that cold.



The power cord itself appears to be OK and it seems to be connected correctly at the block. I took an ohmmeter to the plug, and it indicated nothing (no discernable needle movement) between any two of the three prongs. But it was a dime-store variety cheapie that might not have registered well if the element has very high resistance. So I’m not sure what to do next? I don't really want to remove the power cord completely and check each wire if I can keep from it. But maybe that's the next logical step?

 

[Truckie]

Tulsa618 Try a different volt meater if you have one or go with the old fail safe when the truck is cold plug it in and see what happens in an hour or two. You should know then. When I check mine I just listen for the electrical connection when you plug the plug in and also look for the small blue arc when plugging it in. Hope this helps you.

Mike

 

[ecpeters]

If you have no reading across the plug prongs you may just have a bad plug like mine. I had to replace the plug on my truck last winter. I have been told it is a common problem with the heaters. cut the plug off @ 1 inch back and check the wires for a reading with the ohm meter. Best of luck.

 

[JR2]

I have plugged mine in during the summer and still hear the tell tale pops and cracks. There has to be a way to see if its drawing current... could you not plug it in almost all the way and measure the current draw somehow??



John

 

[Cliffman]

What about pluging it in and putting a temp gun on it. Just a thought

 

[B.G. Smith]

Heater

Get the el-cheapo meter back out. Look at the probes on the meter, make sure they are plugged into the ohm plug and common. Turn meter on and to highest ohm scale, probably has like 0-100, 1,000, 10,000, etc. Touch the probes together, you should get something on the meter, if nothing happens, throw meter over fence and go back in house. If you get a reading on meter continue as follows, with meter still set on high setting, attach one lead to each flat prong of the heater plug, if no reading, cut plug off and test as before touching leads to white and black lead, if you get reading, install new plug and you should be in business, if no reading I would go all the to where the wires tie into heater and again test between white and black wire, if still no reading, heater is bad. bg

 

[jrobinson2]

Have you tried just plugging it in and listening for the sizzle, I've plugged in after driving with the engine at 180* and always heard the sizzle even if the engine was hot, If you don't get any noise then break out the meter and start chasin ohms.

Jared

 

[Loren]

Bruce,



Mine reads 20 ohms between the two power prongs on the truck's plug. That is between the two flat connectors, not the ground.



Mine works.



It's about 60 degrees where the truck is parked. I plugged it in, and within 15 seconds I could hear the hissing/crackling noise from the engine with the hood open.



If yours doesn't hiss/crackle when you plug your heater in, I'd guess it's bad. There are several posts on troubleshooting and fixing it. You can do a search.



Good luck.

Loren

 

[SRadke]

I had one burn out. I bought a new one of higher wattage from my local Napa and put it in. They are really pretty simple to change.

-Scott

 

[Mtngoat]

Can you leave the heater plugged in all the time the truck is'nt being used, or should you plug it in before you use it. I have heard both ways.



Robin

 

[IWeiny]

hiss/crackle?

What is making that noise? I assume it is nothing bad.



Just curious, out here in San Jose I have never used the heater!

 

[JPLB22]

Mtngoat

I don't have an answere to your question as I wondered the same thing every morning last winter. I am not a morning person, so for me getting up two hours early to plug in the truck sucks !! But I no longer have to get up early to plug in truck . Somebody about two weeks ago had a post that suggested using a lamp timer to turn the heater on for you ( sorry I can't remember who it was, to give credit ). I have used it three times so far this year when we had a little cold front move through. And I plan on using it everyday when winter really hits. For some reason I personally don't feel comfortable with it running the heater all night.



Jeff

 

[Shovelhead]

The block heater pulls around 750 watts so make sure you're using a properly rated timer, or you might "Heat" the entire garage by accident.

 

[WestTN]

testing block heater

I am not sure of the wattage rating of the block heater, but to find the resistance of a known wattage heater, you divide the wattage by the voltage to find the amperage. Then divide the voltage by the amperage to find the resistance. Example: If the heater is 360 watts, then 360/120=3 amps. Then divide 120/3=40 ohms. A 500 watt element would be about 29 ohms. You should be able to read this range on any ohmeter.

 

[Tulsa618]

Lots of great feedback, guys! I'm pretty convinced I've either toasted the heater element (possible, since the Beast spent almost every work day last winter plugged in during typical 13-16 hour work days), or I've "pulled" the plug from one too many times backing of the garage only to see a 25' powercord spring back to the wall. I guess I'll cut the plug off first and see if the wiring then shows I have a complete circuit. If not, I guess I'll be NAPA bound. Thanks for your help and suggestions.

 

[illflem]

Re: Mtngoat

Originally posted by IWeiny

What is making that noise? I assume it is nothing bad.

The sound is the coolant boiling around the heater element.

Originally posted by JPLB22

For some reason I personally don't feel comfortable with it running the heater all night.

The only thing it will hurt is your power bill. I've left mine plugged in for weeks on end day and night for the past eight winters except when driving with no ill effects. Mine is controlled by a thermostat set to go on at 40° since I live where I work and don't have a consistent driving schedule. Original heater element.

Cheap NW power is nice also.

 

[SRadke]

I bought a timer from Grainger for mine. You can set the time of day to turn on and off and even cycle it multiple times in a day of you desire. It works great and was only about $50 and is a nice heavy duty unit in a matal case.

-Scott

 

[Tulsa618]

I decided against cutting the plug off in case it was OK. I disconnected the line at the heater element itself and the circuit was fine, so I headed off to get a new element. Holy Moley! Dodge wanted $62. 50 for it – and of course it was not a warranty item … So I called Cummins. They wanted $21. 50. That was a little more reasonable . Since Cummins is on the other side of town (Kansas City), I called Kenworth right down the road. Since they drove to Cummins daily, they said they’d just pick it up for me. It wasn’t three hours and they called for me to come and get it! When I picked it up, the price had changed. Down. To $20. 23. ‘Can’t beat it. But then the fun began…



I didn’t think I’d EVER get that old element removed! Getting a socket into it wasn’t too tough. However, breaking that thing loose was hell! My largest span was my 25-250 ft/lb torque wrench, so I used it. It broke. :{ So the $120 Dodge wanted to replace the element wouldn’t have been so expensive after all! I finally used a cheater (handle from my hydraulic jack) and got it to s l o w l y give. (Hard to believe since the torque on that puppy is 32 ft/lb…!)



The new one went in and everything buttoned up with little effort. At plug-in there was that reassuring little sizzling sound, so I’m finally back on track for winter.



Thanks for all the help and feedback!

 

[illflem]

The heater for a 12 valve must be entirely different, always thought they were the same. On a 12 the heater isn't screwed in at all, there is an allan head screw the center that causes the outside of the heater to expand sealing it in.

You found out the hard way why the instructions that come with most torque wenches say not to use them for breaking nuts loose.

Hope you used anti-seize on your new one

 

[Tulsa618]

Using a torque wrench inappropriately was a really bad miss on my part. My brain just shut down as was scrambling to find something - ANYTHING - that could break that sucker loose. It's lessons like this that one doesn't soon forget!